Senate Minority Leader Howard H. Baker Jr. (R-Tenn.) said yesterday he expects the second Panama Canal Treaty to be approved despite "a fantastic array of discontent" over the entire treaty package.

"My hunch is that . . . in the final analysis, it will settle down with a vote or two on the plus side," Baker said of the treaty dispute in an interview on "Face the Nation" (CBS, WTOP).

The second treaty vote is scheduled for 6 p.m. Tuesday. Two-thirds of all senators present and voting are needed to approve the measure, designed to transfer the canal to Panamanian control by Dec. 31, 1999.

On March 16 the Senate voted 68 to 32, one vote more than the needed two-third majority, to approve a treaty aimed at ensuring the neutrality of the waterway. However, the first accord contained a reservation, proposed by Sen. Dennis DeConcini (D-Ariz.), that would give the United States the unilateral right to use armed force to keep the canal open after the year 2000.

The DeConcini reservation alarmed many Latin Americans, including the Panamanian leader, Gen. Omar Torrijos, who last month sent a letter to 115 nations expressing his concern over the Senate's demand for the right to intervene militarily in Panama.

Baker said yesterday he was surprised by the protests.

"I was not advised of the acute concerns that the Panamanians apparently had about the DeConcini amendment until well after the fact," he said.

"As a matter of fact," he continued, "the first time I heard about it (Panamanian reaction) was when they posted the letter with member states of he United Nations, claiming this was a violation of the U.N. charter - (An action) which I found very provoking . . .

Baker said pro-treaty senators already are involved in a "very difficult situation . . . trying to hang on thise make their to the 115 nations treaties." For the Panamanians to "without notice to many of us in the Sanate, was both a surprise and ,I thought, not the wisest sort of diplomacy," Baker said.

However, Baker was cautiously optimistic that the controversy would not sink the second tresty. He said only one Republican, Sen. S.I. Hayakawa of California, may swictch from a "Yes" vote on the first treaty to a "No" vote on the second. "And I'm not at all sure that we will lose him," Baker said.

Hayakawa has said he is disturbed by the Carter administration's foreign policy progeam, particularly the administration's dealings with communist nations. He is sheheduled to meet with the president before the Tuesday vote.

"My hunch is that it would be harder to swith the vote than it would be to stand pat," Baker said of the possibility of pro-treaty senators voting "No" on the second pact. "But we have such a fantastitic array of discontest on this thing. Idon't know how we're going to treat with it finally or how many rationales there may be for the final decisions. My guess is that, in the final analysis, it will finally settle down with a vote or two on the plus side."

On other matters, Baker said:

Congress would approve the sale of military aircraft to Egypt and Saudi Arabia if President Carter is willing to accept minor "modifications" in the sale plans.

The only way to stimulate the economy and, as a result, eventually bring about a balanced federal budget is to grant Americans a substantial across-the -board tax cut that could lead to a "staggering" federal deficit of $80 billion for one year.